Understanding the effects of ethanol on simple behaviors such as locomotion provides a foundation for understanding more complex behaviors, such as ethanol self-administration and addiction. Further, studies with psychostimulants such as cocaine and amphetamine, and with ethanol as well, have revealed an overlap in the brain systems underlying both the locomotor and reinforcing effects of drugs. However, the neural substrates of ethanol-induced locomotion have not been as extensively studied. The goal of this proposal is to determine the neural bases for ethanol-induced locomotion. Brain lesions of areas within the mesolimbic dopamine system and the extended amygdala will be used to determine the neuroanatomical basis of the locomotor response to ethanol. In addition, microdialysis within these systems will be used to investigate the neurochemical events that are possibly correlated with this behavior. All of the experiments described in this proposal will utilize a genetic animal model of increased (FAST) and decreased (SLOW) sensitivity to ethanol's stimulant effects. This model of differential ethanol sensitivity is useful for examining behavioral and neurophysiological events that are genetically correlated to the locomotor response to ethanol.